/** @file
Device Path services. The thing to remember is device paths are built out of
nodes. The device path is terminated by an end node that is length
sizeof(EFI_DEVICE_PATH_PROTOCOL). That would be why there is sizeof(EFI_DEVICE_PATH_PROTOCOL)
all over this file.
The only place where multi-instance device paths are supported is in
environment varibles. Multi-instance device paths should never be placed
on a Handle.
Copyright (c) 2013, Intel Corporation. All rights reserved.<BR>
This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution. The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php.
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
**/
#include "UefiDevicePathLib.h"
GLOBAL_REMOVE_IF_UNREFERENCED EFI_DEVICE_PATH_UTILITIES_PROTOCOL *mDevicePathLibDevicePathUtilities = NULL;
GLOBAL_REMOVE_IF_UNREFERENCED EFI_DEVICE_PATH_TO_TEXT_PROTOCOL *mDevicePathLibDevicePathToText = NULL;
GLOBAL_REMOVE_IF_UNREFERENCED EFI_DEVICE_PATH_FROM_TEXT_PROTOCOL *mDevicePathLibDevicePathFromText = NULL;
/**
The constructor function caches the pointer to DevicePathUtilites protocol,
DevicePathToText protocol and DevicePathFromText protocol.
The constructor function locates these three protocols from protocol database.
It will caches the pointer to local protocol instance if that operation fails
and it will always return EFI_SUCCESS.
@param ImageHandle The firmware allocated handle for the EFI image.
@param SystemTable A pointer to the EFI System Table.
@retval EFI_SUCCESS The constructor always returns EFI_SUCCESS.
**/
EFI_STATUS
EFIAPI
UefiDevicePathLibOptionalDevicePathProtocolConstructor (
IN EFI_HANDLE ImageHandle,
IN EFI_SYSTEM_TABLE *SystemTable
)
{
EFI_STATUS Status;
Status = gBS->LocateProtocol (
&gEfiDevicePathUtilitiesProtocolGuid,
NULL,
(VOID**) &mDevicePathLibDevicePathUtilities
);
ASSERT_EFI_ERROR (Status);
ASSERT (mDevicePathLibDevicePathUtilities != NULL);
return Status;
}
/**
Returns the size of a device path in bytes.
This function returns the size, in bytes, of the device path data structure
specified by DevicePath including the end of device path node.
If DevicePath is NULL or invalid, then 0 is returned.
@param DevicePath A pointer to a device path data structure.
@retval 0 If DevicePath is NULL or invalid.
@retval Others The size of a device path in bytes.
**/
UINTN
EFIAPI
GetDevicePathSize (
IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath
)
{
if (mDevicePathLibDevicePathUtilities != NULL) {
return mDevicePathLibDevicePathUtilities->GetDevicePathSize (DevicePath);
} else {
return UefiDevicePathLibGetDevicePathSize (DevicePath);
}
}
/**
Creates a new copy of an existing device path.
This function allocates space for a new copy of the device path specified by DevicePath.
If DevicePath is NULL, then NULL is returned. If the memory is successfully
allocated, then the contents of DevicePath are copied to the newly allocated
buffer, and a pointer to that buffer is returned. Otherwise, NULL is returned.
The memory for the new device path is allocated from EFI boot services memory.
It is the responsibility of the caller to free the memory allocated.
@param DevicePath A pointer to a device path data structure.
@retval NULL DevicePath is NULL or invalid.
@retval Others A pointer to the duplicated device path.
**/
EFI_DEVICE_PATH_PROTOCOL *
EFIAPI
DuplicateDevicePath (
IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath
)
{
if (mDevicePathLibDevicePathUtilities != NULL) {
return mDevicePathLibDevicePathUtilities->DuplicateDevicePath (DevicePath);
} else {
return UefiDevicePathLibDuplicateDevicePath (DevicePath);
}
}
/**
Creates a new device path by appending a second device path to a first device path.
This function creates a new device path by appending a copy of SecondDevicePath
to a copy of FirstDevicePath in a newly allocated buffer. Only the end-of-device-path
device node from SecondDevicePath is retained. The newly created device path is
returned. If FirstDevicePath is NULL, then it is ignored, and a duplicate of
SecondDevicePath is returned. If SecondDevicePath is NULL, then it is ignored,
and a duplicate of FirstDevicePath is returned. If both FirstDevicePath and
SecondDevicePath are NULL, then a copy of an end-of-device-path is returned.
If there is not enough memory for the newly allocated buffer, then NULL is returned.
The memory for the new device path is allocated from EFI boot services memory.
It is the responsibility of the caller to free the memory allocated.
@param FirstDevicePath A pointer to a device path data structure.
@param SecondDevicePath A pointer to a device path data structure.
@retval NULL If there is not enough memory for the newly allocated buffer.
@retval NULL If FirstDevicePath or SecondDevicePath is invalid.
@retval Others A pointer to the new device path if success.
Or a copy an end-of-device-path if both FirstDevicePath and SecondDevicePath are NULL.
**/
EFI_DEVICE_PATH_PROTOCOL *
EFIAPI
AppendDevicePath (
IN CONST EFI_DEVICE_PATH_PROTOCOL *FirstDevicePath, OPTIONAL
IN CONST EFI_DEVICE_PATH_PROTOCOL *SecondDevicePath OPTIONAL
)
{
if (mDevicePathLibDevicePathUtilities != NULL) {
return mDevicePathLibDevicePathUtilities->AppendDevicePath (FirstDevicePath, SecondDevicePath);
} else {
return UefiDevicePathLibAppendDevicePath (FirstDevicePath, SecondDevicePath);
}
}
/**
Creates a new path by appending the device node to the device path.
This function creates a new device path by appending a copy of the device node
specified by DevicePathNode to a copy of the device path specified by DevicePath
in an allocated buffer. The end-of-device-path device node is moved after the
end of the appended device node.
If DevicePathNode is NULL then a copy of DevicePath is returned.
If DevicePath is NULL then a copy of DevicePathNode, followed by an end-of-device
path device node is returned.
If both DevicePathNode and DevicePath are NULL then a copy of an end-of-device-path
device node is returned.
If there is not enough memory to allocate space for the new device path, then
NULL is returned.
The memory is allocated from EFI boot services memory. It is the responsibility
of the caller to free the memory allocated.
@param DevicePath A pointer to a device path data structure.
@param DevicePathNode A pointer to a single device path node.
@retval NULL If there is not enough memory for the new device path.
@retval Others A pointer to the new device path if success.
A copy of DevicePathNode followed by an end-of-device-path node
if both FirstDevicePath and SecondDevicePath are NULL.
A copy of an end-of-device-path node if both FirstDevicePath
and SecondDevicePath are NULL.
**/
EFI_DEVICE_PATH_PROTOCOL *
EFIAPI
AppendDevicePathNode (
IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath, OPTIONAL
IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePathNode OPTIONAL
)
{
if (mDevicePathLibDevicePathUtilities != NULL) {
return mDevicePathLibDevicePathUtilities->AppendDeviceNode (DevicePath, DevicePathNode);
} else {
return UefiDevicePathLibAppendDevicePathNode (DevicePath, DevicePathNode);
}
}
/**
Creates a new device path by appending the specified device path instance to the specified device
path.
This function creates a new device path by appending a copy of the device path
instance specified by DevicePathInstance to a copy of the device path specified
by DevicePath in a allocated buffer.
The end-of-device-path device node is moved after the end of the appended device
path instance and a new end-of-device-path-instance node is inserted between.
If DevicePath is NULL, then a copy if DevicePathInstance is returned.
If DevicePathInstance is NULL, then NULL is returned.
If DevicePath or DevicePathInstance is invalid, then NULL is returned.
If there is not enough memory to allocate space for the new device path, then
NULL is returned.
The memory is allocated from EFI boot services memory. It is the responsibility
of the caller to free the memory allocated.
@param DevicePath A pointer to a device path data structure.
@param DevicePathInstance A pointer to a device path instance.
@return A pointer to the new device path.
**/
EFI_DEVICE_PATH_PROTOCOL *
EFIAPI
AppendDevicePathInstance (
IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath, OPTIONAL
IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePathInstance OPTIONAL
)
{
if (mDevicePathLibDevicePathUtilities != NULL) {
return mDevicePathLibDevicePathUtilities->AppendDevicePathInstance (DevicePath, DevicePathInstance);
} else {
return UefiDevicePathLibAppendDevicePathInstance (DevicePath, DevicePathInstance);
}
}
/**
Creates a copy of the current device path instance and returns a pointer to the next device path
instance.
This function creates a copy of the current device path instance. It also updates
DevicePath to point to the next device path instance in the device path (or NULL
if no more) and updates Size to hold the size of the device path instance copy.
If DevicePath is NULL, then NULL is returned.
If DevicePath points to a invalid device path, then NULL is returned.
If there is not enough memory to allocate space for the new device path, then
NULL is returned.
The memory is allocated from EFI boot services memory. It is the responsibility
of the caller to free the memory allocated.
If Size is NULL, then ASSERT().
@param DevicePath On input, this holds the pointer to the current
device path instance. On output, this holds
the pointer to the next device path instance
or NULL if there are no more device path
instances in the device path pointer to a
device path data structure.
@param Size On output, this holds the size of the device
path instance, in bytes or zero, if DevicePath
is NULL.
@return A pointer to the current device path instance.
**/
EFI_DEVICE_PATH_PROTOCOL *
EFIAPI
GetNextDevicePathInstance (
IN OUT EFI_DEVICE_PATH_PROTOCOL **DevicePath,
OUT UINTN *Size
)
{
if (mDevicePathLibDevicePathUtilities != NULL) {
return mDevicePathLibDevicePathUtilities->GetNextDevicePathInstance (DevicePath, Size);
} else {
return UefiDevicePathLibGetNextDevicePathInstance (DevicePath, Size);
}
}
/**
Creates a device node.
This function creates a new device node in a newly allocated buffer of size
NodeLength and initializes the device path node header with NodeType and NodeSubType.
The new device path node is returned.
If NodeLength is smaller than a device path header, then NULL is returned.
If there is not enough memory to allocate space for the new device path, then
NULL is returned.
The memory is allocated from EFI boot services memory. It is the responsibility
of the caller to free the memory allocated.
@param NodeType The device node type for the new device node.
@param NodeSubType The device node sub-type for the new device node.
@param NodeLength The length of the new device node.
@return The new device path.
**/
EFI_DEVICE_PATH_PROTOCOL *
EFIAPI
CreateDeviceNode (
IN UINT8 NodeType,
IN UINT8 NodeSubType,
IN UINT16 NodeLength
)
{
if (mDevicePathLibDevicePathUtilities != NULL) {
return mDevicePathLibDevicePathUtilities->CreateDeviceNode (NodeType, NodeSubType, NodeLength);
} else {
return UefiDevicePathLibCreateDeviceNode (NodeType, NodeSubType, NodeLength);
}
}
/**
Determines if a device path is single or multi-instance.
This function returns TRUE if the device path specified by DevicePath is
multi-instance.
Otherwise, FALSE is returned.
If DevicePath is NULL or invalid, then FALSE is returned.
@param DevicePath A pointer to a device path data structure.
@retval TRUE DevicePath is multi-instance.
@retval FALSE DevicePath is not multi-instance, or DevicePath
is NULL or invalid.
**/
BOOLEAN
EFIAPI
IsDevicePathMultiInstance (
IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath
)
{
if (mDevicePathLibDevicePathUtilities != NULL) {
return mDevicePathLibDevicePathUtilities->IsDevicePathMultiInstance (DevicePath);
} else {
return UefiDevicePathLibIsDevicePathMultiInstance (DevicePath);
}
}
/**
Locate and return the protocol instance identified by the ProtocolGuid.
@param ProtocolGuid The GUID of the protocol.
@return A pointer to the protocol instance or NULL when absent.
**/
VOID *
UefiDevicePathLibLocateProtocol (
EFI_GUID *ProtocolGuid
)
{
EFI_STATUS Status;
VOID *Protocol;
Status = gBS->LocateProtocol (
ProtocolGuid,
NULL,
(VOID**) &Protocol
);
if (EFI_ERROR (Status)) {
return NULL;
} else {
return Protocol;
}
}
/**
Converts a device node to its string representation.
@param DeviceNode A Pointer to the device node to be converted.
@param DisplayOnly If DisplayOnly is TRUE, then the shorter text representation
of the display node is used, where applicable. If DisplayOnly
is FALSE, then the longer text representation of the display node
is used.
@param AllowShortcuts If AllowShortcuts is TRUE, then the shortcut forms of text
representation for a device node can be used, where applicable.
@return A pointer to the allocated text representation of the device node or NULL if DeviceNode
is NULL or there was insufficient memory.
**/
CHAR16 *
EFIAPI
ConvertDeviceNodeToText (
IN CONST EFI_DEVICE_PATH_PROTOCOL *DeviceNode,
IN BOOLEAN DisplayOnly,
IN BOOLEAN AllowShortcuts
)
{
if (mDevicePathLibDevicePathToText == NULL) {
mDevicePathLibDevicePathToText = UefiDevicePathLibLocateProtocol (&gEfiDevicePathToTextProtocolGuid);
}
if (mDevicePathLibDevicePathToText != NULL) {
return mDevicePathLibDevicePathToText->ConvertDeviceNodeToText (DeviceNode, DisplayOnly, AllowShortcuts);
}
return UefiDevicePathLibConvertDeviceNodeToText (DeviceNode, DisplayOnly, AllowShortcuts);
}
/**
Converts a device path to its text representation.
@param DevicePath A Pointer to the device to be converted.
@param DisplayOnly If DisplayOnly is TRUE, then the shorter text representation
of the display node is used, where applicable. If DisplayOnly
is FALSE, then the longer text representation of the display node
is used.
@param AllowShortcuts If AllowShortcuts is TRUE, then the shortcut forms of text
representation for a device node can be used, where applicable.
@return A pointer to the allocated text representation of the device path or
NULL if DeviceNode is NULL or there was insufficient memory.
**/
CHAR16 *
EFIAPI
ConvertDevicePathToText (
IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath,
IN BOOLEAN DisplayOnly,
IN BOOLEAN AllowShortcuts
)
{
if (mDevicePathLibDevicePathToText == NULL) {
mDevicePathLibDevicePathToText = UefiDevicePathLibLocateProtocol (&gEfiDevicePathToTextProtocolGuid);
}
if (mDevicePathLibDevicePathToText != NULL) {
return mDevicePathLibDevicePathToText->ConvertDevicePathToText (DevicePath, DisplayOnly, AllowShortcuts);
}
return UefiDevicePathLibConvertDevicePathToText (DevicePath, DisplayOnly, AllowShortcuts);
}
/**
Convert text to the binary representation of a device node.
@param TextDeviceNode TextDeviceNode points to the text representation of a device
node. Conversion starts with the first character and continues
until the first non-device node character.
@return A pointer to the EFI device node or NULL if TextDeviceNode is NULL or there was
insufficient memory or text unsupported.
**/
EFI_DEVICE_PATH_PROTOCOL *
EFIAPI
ConvertTextToDeviceNode (
IN CONST CHAR16 *TextDeviceNode
)
{
if (mDevicePathLibDevicePathFromText == NULL) {
mDevicePathLibDevicePathFromText = UefiDevicePathLibLocateProtocol (&gEfiDevicePathFromTextProtocolGuid);
}
if (mDevicePathLibDevicePathFromText != NULL) {
return mDevicePathLibDevicePathFromText->ConvertTextToDeviceNode (TextDeviceNode);
}
return UefiDevicePathLibConvertTextToDeviceNode (TextDeviceNode);
}
/**
Convert text to the binary representation of a device path.
@param TextDevicePath TextDevicePath points to the text representation of a device
path. Conversion starts with the first character and continues
until the first non-device node character.
@return A pointer to the allocated device path or NULL if TextDeviceNode is NULL or
there was insufficient memory.
**/
EFI_DEVICE_PATH_PROTOCOL *
EFIAPI
ConvertTextToDevicePath (
IN CONST CHAR16 *TextDevicePath
)
{
if (mDevicePathLibDevicePathFromText == NULL) {
mDevicePathLibDevicePathFromText = UefiDevicePathLibLocateProtocol (&gEfiDevicePathFromTextProtocolGuid);
}
if (mDevicePathLibDevicePathFromText != NULL) {
return mDevicePathLibDevicePathFromText->ConvertTextToDevicePath (TextDevicePath);
}
return UefiDevicePathLibConvertTextToDevicePath (TextDevicePath);
}